Systems and methods for automatically and semiautomatically controlling aircraft refueling
Aerial refueling systems and associated methods are disclosed. A system in accordance with one embodiment of the invention includes an operator input device configured to receive operator inputs and direct a first input signal corresponding to a target position for an aerial refueling device. A sensor can be positioned to detect a location of at least one of the aerial refueling device and a receiver aircraft, and can be configured to direct a second input signal. A controller can be operatively coupled to the operator input device and the sensor to receive the first and second input signals and direct a command signal to adjust the position of the aerial refueling device in response to both the first and second input signals, unless either or both of the input signals are absent or below a threshold value. Accordingly, the system can respond to both automatically generated sensor data and data input by an operator. A fully automated version of the system can be installed on an unmanned aircraft having additional capabilities, for example, electronic surveillance and/or jamming capabilities.
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The present invention is directed generally toward systems and methods for automatically and semiautomatically refueling aircraft, including systems and methods that incorporate operator input and sensor input when coupling receiver aircraft to refueling devices.
BACKGROUNDIn-flight refueling (or air-to-air refueling) is an important method for extending the range of aircraft traveling long distances over areas having no feasible landing or refueling points. Although in-flight refueling is a relatively common operation, especially for military aircraft, the aircraft to be refueled (e.g., the receiver aircraft) must be precisely positioned relative to the tanker aircraft in order to provide safe engagement while the fuel is dispensed to the receiver aircraft. The requirement for precise relative spatial positioning of the two rapidly moving aircraft makes in-flight refueling a challenging operation.
There are currently two primary systems for in-flight refueling. One is a hose and drogue system, which includes a refueling hose having a drogue disposed at one end. The hose and drogue are trailed behind the tanker aircraft once the tanker aircraft is on station. The pilot of the receiver aircraft then flies the receiver aircraft to intercept and couple with the drogue for refueling. Another existing system is a boom refueling system. The boom refueling system typically includes a rigid boom extending from the tanker aircraft, with a probe and nozzle at its distal end. The boom also includes airfoils controlled by a boom operator stationed on the refueling aircraft. The airfoils allow the boom operator to actively maneuver the boom with respect to the receiver aircraft, which flies in a fixed refueling position below and aft of the tanker aircraft.
One approach to addressing the challenge associated with precisely positioning the tanker aircraft relative to the receiver aircraft is to automate the process. For example, one existing arrangement includes using cameras housed in the tanker aircraft to determine the distance between the receiver aircraft and the tip of a refueling boom carried by the tanker aircraft. The system can then be used to automatically control the position of the boom to mate with a corresponding refueling receptacle of the receiver aircraft. The system can be configured to allow the boom operator to take control of the movement of the boom, for example, if the automatic system malfunctions or if for any reason the refueling boom must be directed away from the receiver aircraft. While generally effective, this approach may not provide the optimum level of controllability in all refueling situations.
SUMMARYThe following summary is provided for the benefit of the reader only, and does not limit the invention as set forth by the claims. The invention is directed generally toward systems and methods for automatically and/or semiautomatically refueling aircraft. A system in accordance with one aspect of the invention includes an operator input device configured to receive operator inputs and direct a first input signal corresponding to a target position for an aerial refueling device. The system can further include a sensor positioned to detect a location of at least one of the aerial refueling device and a receiver aircraft. The sensor can be configured to direct a second input signal corresponding to a location of at least one of the aerial refueling device and the receiver aircraft. The system can still further include a controller operatively coupled to the operator input device and the sensor to receive the first and second input signals. The controller can be configured to direct a command signal to adjust the position of the aerial refueling device in response to both the first and second input signals, unless either or both of the first and second input signals are absent or below a threshold value.
In particular aspects of the invention, the controller is configured to sum signals based at least in part on the first and second signals and direct the command signal based on the sum. In further particular aspects, the controller can be configured to sum portions of the first and second signals corresponding to motion along a first axis independently of portions of the first and second signals corresponding to motion along a second (e.g., orthogonal) axis.
A method in accordance with another aspect of the invention is directed to refueling an aircraft in flight. The method can include receiving a first signal from an operator input device, with the first signal corresponding to a target position for an aerial refueling device. The method can further include receiving a second input signal from a sensor, with the second input signal corresponding to the position of at least one of the aerial refueling device and a receiver aircraft. The method can still further include directing a change in the position of the aerial refueling device based on both the first and second input signals, unless at least one of the first and second input signals is absent or below a threshold value.
Still another aspect of the invention is directed to an unmanned aerial refueling system. The system can include an unmanned aircraft carrying a refueling device, and a controller configured to automatically control a position of the refueling device relative to a receiver aircraft. The system can still further include an electronic facility that is configured to be projected from the unmanned aircraft, e.g., for surveillance and/or electronic jamming. Accordingly, the system can serve as an unmanned strike support aircraft with a refueling capability.
Existing automated aerial refueling systems provide several advantages over a purely manual boom positioning arrangement. However, these systems may not be ideal in all situations. For example, these systems are typically configured to operate in one of two mutually exclusive modes: a first mode in which positioning the boom is completely automated, or a second mode in which positioning the boom is completely manual. However, these systems are unable to handle a situation in which the boom operator may wish to assist, but not take over, control of the boom.
The present disclosure describes systems for automatically refueling aircraft, including systems that receive inputs from both sensors and a human operator. Certain specific details are set forth in the following description and in
Many embodiments of the invention described below may take the form of computer-executable instructions, including routines executed by a programmable computer. Those skilled in the relevant art will appreciate that the invention can be practiced on computer systems other than those shown and described below. The invention can be embodied in a special-purpose computer or data processor that is specifically programmed, configured or constructed to perform one or more of the computer-executable instructions described below. Accordingly, the term “computer” as generally used herein refers to any data processor and can include Internet appliances and hand-held devices (including palm-top computers, wearable computers, cellular or mobile phones, multi-processor systems, processor-based or programmable consumer electronics, network computers, mini computers and the like). Information handled by these computers can be presented at any suitable display medium, including a CRT display or LCD.
The information can also be practiced in distributed environments, where tasks or modules are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules or subroutines may be located in local and remote memory storage devices. Aspects of the invention described below may be stored or distributed on computer-readable media, including magnetic or optically readable or removable computer disks, as well as distributed electronically over networks. Data structures and transmissions of data particular to aspects of the invention are also encompassed within the scope of the invention.
In one embodiment, the aerial refueling device 120 can include the boom 121. Accordingly, the controller 230 can direct actuation of the control surfaces 122 to provide for lateral motion of the boom 121 (as indicated by arrow A) and vertical or pitch motion of the boom 121 (as indicated by arrow B). The controller 230 can also control axial actuation of a deployable boom tip 123, as indicated by arrow C.
In a particular aspect of this embodiment, the controller 230 can be coupled to an actuator 252 that is in turn coupled to the operator input device 250 to provide feedback to the operator. Accordingly, when the controller 230 directs a command signal to move the boom 121 in a particular manner, a corresponding command signal can be directed to the actuator 252 to move the operator input device 250 in a corresponding manner. As a result, an operator placing a hand very lightly on the joystick 251 will feel the joystick 251 move in a manner that tracks the motion of the boom 121, and in a manner that is commanded by the controller 230 based upon the sensor 240. If the operator places any force (e.g., greater than a threshold level of force) on the joystick 251, the operator's input can also influence the position of the boom 121. In a particular aspect of this embodiment, the rate at which the controller 230 will direct a motion of the boom 121 based on the operator's input, will vary proportionately to the force applied by the operator to the operator input device 250. Suitable operator input devices 250 for performing this function are available from MPC Products Corporation of Skokie, Ill.
In process portion 306, the process 300 can include automatically determining an error between the actual boom position and a target boom position, based on the second input signal. The authority granted to the automatic motion control of the aerial refueling device can then be limited (process portion 308). Accordingly, process portion 308 can prevent the automatic portion of the system from overwhelming a large manual operator input. The process can then include directing the motion of the aerial refueling device to reduce the error, based on both the first and second signals (process portion 310).
In a particular embodiment, process portion 310 can include directing the motion of the aerial refueling device based on both the first and second signals, unless either or both input signals are absent or below a threshold value. For example, if the operator applies no force to the operator input device (or applies a very small force), then the system can direct the motion of the boom based entirely on the automatically determined position error value. Conversely, if the automatically determined position error value is zero (e.g., the aerial refueling device is accurately positioned for refueling), but the operator applies a force to the operator input device, the system will allow the operator to override the automatically determined position error value. The system can continuously monitor both the first and second signals so as to seamlessly transition between fully automated motion, fully manual motion and motion based on both manual and automated inputs.
One feature of several embodiments of the systems and methods described above with reference to
Another advantage of the foregoing feature is that it can allow the operator and the automated sensors to simultaneously control different aspects of the motion of the refueling device. For example, the operator may wish to automatically have the boom aligned laterally with the refueling receptacle, but have the tip of the boom above the receiver aircraft (e.g., to allow the pilot of the receiver aircraft greater flexibility in positioning his aircraft, or for other reasons). Accordingly, the boom operator can apply a pitch-directed force to the input device to control the pitch of the boom, while allowing the operator input device to move laterally, thereby allowing the automated portion of the system to direct the lateral motion of the boom. In other embodiments, the motion can be divided between the operator and the automated sensor in different manners. For example, the automated sensor can be used to control both the pitch and lateral position of the boom, and the operator can control the extension or retraction of the probe tip.
Still another advantage of features of several of the foregoing embodiments is that they can be used to gradually shift from a fully manual boom operation to a fully automated boom operation. For example, during system testing, pilot training, and/or boom operator training, the operator can remain in the control loop to position the boom for as long as it takes for the operator, the tanker aircraft pilot, and the receiver aircraft pilot to become comfortable with the automated motion of the boom. The operator can gradually reduce the input he or she provides as this comfort level increases, and can ultimately oversee a completely hands-off operation, while remaining available to intervene for an emergency breakaway procedure or other acute procedure.
As described above, the foregoing system can, in some cases, be used in a fully automated manner to direct the motion of the aerial refueling device without any human intervention. Accordingly, this system can be installed on unmanned aerial refueling aircraft. Examples of such aircraft are illustrated in
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the invention. For example, the signals transmitted by the sensor may include a visual indication of the receiver aircraft and/or the refueling system, or these signals can include other characteristics (e.g., the position of the boom relative to the tanker aircraft, based on input from displacement sensors). Aspects of the invention described in the context of particular embodiments may be combined or eliminated in other embodiments. For example, the refueling systems can be installed on aircraft having configurations other than those described above, and/or can be used to control aerial refueling devices other than those described above (e.g., hose and drogue devices). Further, while advantages associated with certain embodiments of the invention have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, the invention is not limited, except as by the appended claims.
Claims
1. An aerial refueling system, comprising:
- an operator input device configured to receive operator inputs and direct a first input signal corresponding to a target position for an aerial refueling device;
- a sensor positioned to detect a location of a receiver aircraft, the sensor being configured to direct a second input signal corresponding to a location of the receiver aircraft; and
- a controller operatively coupled to the operator input device and the sensor to receive both the first and second input signals, the controller being configured to direct a command signal to adjust the position of the aerial refueling device in response to both the first and second input signals.
2. The system of claim 1 wherein the controller is configured to sum signals based at least in part on the first and second signals and direct the command signal based on the sum.
3. The system of claim 1 wherein the controller is configured to sum signals based at least in part on portions of the first and second signals and corresponding to motion along a first axis independently of signals based at least in part on portions of the first and second signals corresponding to motion along a second axis, wherein the second axis is generally orthogonal to the first axis.
4. The system of claim 1 wherein the controller includes a limiter configured to limit the effect of the second input signal when the second input signal corresponds to a target motion greater than a threshold amount.
5. The system of claim 1 wherein the controller is configured to continually receive input signals from both the operator input device and the sensor.
6. The system of claim 1 wherein the controller is configured to direct a command signal based only on the first input signal when the second input signal is absent or below a threshold value, and wherein the controller is configured to direct a command signal based only on the second input signal when the first input signal is absent or below a threshold value.
7. The system of claim 1 wherein at least one of the sensor and the controller is configured to detect a difference in position between the aerial refueling device and the receiver aircraft, and wherein the controller is configured to direct a command signal that moves the aerial refueling device in a direction that reduces the difference in position.
8. The system of claim 1, further comprising an actuator coupled to the controller and the operator input device, the actuator being configured to move the operator input device in a manner that is consistent with the command signal.
9. The system of claim 1 wherein the sensor includes a photosensitive sensor coupled to a target recognition device.
10. The system of claim 1, further comprising the aerial refueling device, and wherein the aerial refueling device includes a deployable boom.
11. The system of claim 1, further comprising:
- the aerial refueling device;
- a tanker aircraft carrying the aerial refueling device; and
- a receiver aircraft positioned proximate to the tanker aircraft.
12. The system of claim 11 wherein the receiver aircraft is an unmanned air vehicle.
13. The system of claim 1, further comprising:
- the aerial refueling device, and wherein the aerial refueling device includes a generally rigid boom that is movable between a stowed position and a deployed position; and
- a tanker aircraft carrying the boom, the controller, the operator input device, and the sensor;
- wherein the sensor includes a plurality of cameras coupled to a target recognition device, the target recognition device including a computer-readable medium containing instructions to recognize at least portions of the boom and a receiver aircraft.
14. The system of claim 1 wherein the controller includes a computer readable medium containing instructions to direct a change in position of the aerial refueling device.
15. An aerial refueling system, comprising:
- input means for receiving operator inputs and directing a first input signal corresponding to a target position for an aerial refueling device;
- sensor means for detecting a location of at least one of the aerial refueling device and a receiver aircraft and directing a second input signal; and
- control means for controlling a position of the aerial refueling device, the control means being operatively coupled to the input means and the sensor means to receive both the first and second input signals, the control means being configured to adjust the position of the aerial refueling device in response to both the first and second input signals.
16. The system of claim 15 wherein the control means is configured to direct a command signal based only on the first input signal when the second input signal is absent or below a threshold value, and wherein the control means is configured to direct a command signal based only on the second input signal when the first input signal is absent or below a threshold value.
17. An aerial refueling system, comprising:
- an operator input device configured to receive operator inputs and direct a first input signal corresponding to a target position for an aerial refueling device;
- a sensor positioned to detect a location of a receiver aircraft, the sensor being configured to direct a second input signal corresponding to a location of the receiver aircraft; and
- a controller operatively coupled to the operator input device and the sensor to receive the first and second input signals, the controller being configured to direct a command signal to adjust the position of the aerial refueling device in response to both the first and second input signals unless either or both of the first and second input signals are absent or below a threshold value, wherein the controller is configured to sum signals based at least in part on the first and second signals and direct the command signal based on the sum.
18. An aerial refueling system, comprising:
- an operator input device configured to receive operator inputs and direct a first input signal corresponding to a target position for an aerial refueling device;
- a sensor positioned to detect a location of a receiver aircraft, the sensor being configured to direct a second input signal corresponding to a location of the receiver aircraft; and
- a controller operatively coupled to the operator input device and the sensor to receive the first and second input signals, the controller being configured to direct a command signal to adjust the position of the aerial refueling device in response to both the first and second input signals unless either or both of the first and second input signals are absent or below a threshold value, wherein the controller includes a limiter configured to limit the effect of the second input signal when the second input signal corresponds to a target motion greater than a threshold amount.
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Type: Grant
Filed: Mar 24, 2005
Date of Patent: Dec 30, 2008
Assignee: The Boeing Company (Chicago, IL)
Inventor: Thomas E. Speer (Seattle, WA)
Primary Examiner: Timothy D Collins
Attorney: Perkins Coie LLP
Application Number: 11/090,347
International Classification: B64D 39/00 (20060101);